I. Field of the Invention
The present invention relates to methods of sampling of fluids, both gases and liquids, generally classified in U.S. Patent Office Class 73, particularly subclasses 863, and most especially subclasses 863.41, 863.71, 863.72, 863.73, 863.81, 863.82, and 863.85.
II. Description of the Prior Art
With refinements in analytical techniques, the need for more sophisticated methods of sampling has become evident to industry. Also, emphasis on environmental consideration has reduced the tolerable amounts of sampling effluents which are acceptable. A number of prior patents have dealt with solutions to prior patents of combining a representative sample with minimum pollution.
U.S. Pat. No. 4,712,434 to Herwig (assigned E C Erdolchemie GmbH) uses a special single four-way valve and a complex flushing mechanism to provide a flow through sample in a transportable container.
U.S. Pat. No. 4,800,763 to Kakkers (assigned VEG-Gasinstituut) teaches periodic sampling from a pipeline, but uses no transportable container.
U.S. Pat. No. 4,800,761 to Spencer provides a flow through sample in a transportable container, but uses a special drill block which incorporates a venturi together with a three-way valve for alternately flushing and filling the container.
U.S. Pat. No. 4,755,357 to Noguchi (assigned Horiba, Ltd) uses a four-way valve or several three-way valves, but requires two parallel capillaries as in a gas-liquid chromatograph and provides no transportable container sample.
U.S. Pat. No. 4,827,775 to Forrester also provides no transportable sample container and performs its sampling within a closed manway with the sample being delivered to a permanently connected pipeline.
U.S. Pat. No. 3,681,997 to Allen (assigned Gulf Refining) is also a pipeline sampler with no transportable container being provided.
U.S. Pat. No. 3,960,500 to Ross (assigned Bailey Meter Co.) utilizes a drop tube device to obtain a representative sample, but provides no transportable sample container.
U.S. Pat. No. 4,167,117 to Stokley (assigned Exxon Production Research Co.) utilizes a pitot-like tube to obtain a representative sample flowing through a pipeline, e.g. sand and crude oil from a well and provides no transportable sample container.
While each of the above prior art are valuable for their intended purposes, none of the references provides, in combination, a flow through sample, a transportable sample container, and the extremely low venting of the sample material which is achieved by the present invention.